Rewrite fypp directive to avoid the use of removesuffix in stdlib_math_meshgrip

[jvdp1]

removesuffix used in stdlib_math_meshgrid requires Python >3.9.

Here is a small change to avoid the requirement of Python >3.9.

@igirault : was there a special need to use removesuffix? Do I overlook something? Or are my changes satisfying?

\cc @perazz @jalvesz

[perazz]

LGTM, thank you @jvdp1. Besides the greater compatibility, I also like your syntax better.

[jalvesz]

LGTM @jvdp1 indeed it looks cleaner this way!!

[perazz]

@jvdp1 I think this can be merged.

[igirault]

@igirault : was there a special need to use removesuffix? Do I overlook something? Or are my changes satisfying?

not at all, this was due to my poor understanding of the join operator in python. This is indeed way nicer with your correction :)

[jvdp1]

Thank you @igirault for your answer.

With all these approvals, I will merge this PR.